CN111479661A

CN111479661A - Method for determining at least one printing process parameter value, computer-readable storage medium and additive manufacturing device

Info

Publication number: CN111479661A
Application number: CN201880080752.XA
Authority: CN
Inventors: A·鲍雷斯
Original assignee: Heraeus Additive Manufacturing GmbH
Current assignee: Heraeus Additive Manufacturing GmbH
Priority date: 2017-12-22
Filing date: 2018-12-12
Publication date: 2020-07-31
Also published as: EP3501758A1; WO2019121241A1; IL275582A; US20210229363A1

Abstract

The problem is solved by a method for determining at least one printing process parameter value (25) for a beam melting process, the method comprising the steps of-loading first and second energy field data (20, 20') from a memory device (11), the first and second energy field data (20, 20') being assigned to an energy field (E1, E2) of at least one track (L1, L2, L3) of the melting process, respectively, -determining (33) a resulting energy field data (24) by superimposing the first energy field data (20) with the second energy field data (20'), determining (34) the at least one printing process parameter value (25) for the at least one printing process parameter of an additive manufacturing apparatus (10) using the resulting energy field data (24).

Description

Method for determining at least one printing process parameter value, computer-readable storage medium and additive manufacturing device

Technical Field

The invention relates to a method, a computer-readable storage medium and an additive manufacturing apparatus for determining at least one printing process parameter value for a beam melting process.

Background

Various methods are known for producing three-dimensional workpieces from one or more liquid or solid materials.

Thus, for example, in so-called "fused deposition modeling" (FDM), a workpiece is built layer by layer from a meltable plastic. In this case, the linear plastic is applied to the plate in the working area by heating and pressing with the aid of a nozzle. The layers may be applied successively on top of each other by means of curing of the plastic.

In stereolithography (S L A), a liquid epoxy is poured into a chamber, wherein the surface of the epoxy is irradiated with a laser in a spot-like manner so that the epoxy is cured at the point of irradiation.

In selective laser sintering (S L S) or selective laser melting (S L M) and electron beam melting (SEBM), a powder bed of powdered plastic, metal or ceramic is first applied to a plate in a chamber.

The selective melting or sintering is preferably carried out by scanning the powder bed by means of high-energy radiation. In this case, the scanning is usually performed in a linear manner within the layer, so that individual tracks, i.e. melted tracks or sintered tracks, are produced. The rails extend at least substantially parallel to each other, wherein the rails may be connected to each other at alternating ends.

Another method for melting or sintering the powder bed is multiple spot exposures. In this case, the continuous melting or sintering point may also not be on a line, but rather virtually randomly distributed over the powder bed. Alternatively, the distribution of melting or sintering points is performed according to a fixed pattern (e.g. a checkerboard pattern). In the following, "point" means a melting point or a sintering point.

After one layer is completed, the build platform is lowered slightly and a new layer is applied. Thus, a printed product is created from the sum of the sequentially applied print layers.

The printing of the printed product by means of the beam melting method thus operates according to the beam melting process, and the printing of the printed product by means of the beam sintering method thus operates according to the beam sintering process.

It has been determined that the geometry to be printed is particularly important for the properties of the printed product, especially in the case of the beam melting method and the beam sintering method. For example, if the material is melted or sintered at short intervals in closely adjacent areas, it can result in local overheating of the material. Due to the high temperature, the cooling takes place relatively slowly there as well, relative to other areas in the component, as a result of which the material properties of the printed product are negatively influenced.

Similar behavior can be determined in the melting or sintering of adjacent tracks. Thus, a rail that has been melted or sintered has an effect on the rail that is to be melted or sintered next. Overall, the described effect leads to inhomogeneous material properties, which may be manifested, for example, by increased brittleness of the printed product.

Therefore, the quality of the printed product varies greatly and leads to unsatisfactory results.

Disclosure of Invention

Starting from this prior art, the object of the present invention is a method, a computer-readable storage medium and an additive manufacturing device for determining at least one printing process parameter value for a beam melting process and/or a beam sintering process, which solve the aforementioned drawbacks. In particular, it is an object of the invention to specify a method which allows printing with substantially uniform material properties of the printed product. Furthermore, it is an object of the invention to specify a method or an additive manufacturing device for reducing the fraction defective. Furthermore, it is an object of the invention to achieve consistent printing results regardless of the geometry to be printed.

This object is achieved by means of a method according to claim 1, a computer readable storage medium according to claim 16 and an additive manufacturing apparatus according to claim 17.

In particular, the object is achieved by means of a method for determining at least one printing process parameter value for a beam melting process and/or a beam sintering process, having the following:

-loading first and second energy field data from a memory device, the first and second energy field data being respectively assigned to an energy field of, in particular, at least one track and/or at least one point, preferably 10 tracks, of, in particular, an adjacent at least one region, in particular of, a melting process or a sintering process;

-determining resulting energy field data by, in particular, digitally superimposing the first energy field data with the second energy field data;

-determining at least one printing process parameter value for at least one printing process parameter of the additive manufacturing device using the resulting energy field data.

The core of the invention is to take into account the energy field of the already melted or sintered region during the melting or sintering of the next region. In the following, the melting or sintering of the regions is referred to in general terms as the print region, wherein in this case two methods are always meant. During printing of an area, there is a temperature rise in the area itself and in its surroundings. If more than two areas adjacent to each other are printed, there is a superposition of the energy fields of the first two areas at the point of the third area that should be printed. Due to varying environmental conditions, in particular varying temperatures of the material to be processed, printing with constant printing process parameter values does not lead to optimal results or constant product characteristics. It is therefore necessary to determine the printing process parameter values for each area separately, wherein even within an area the printing process parameter values may vary depending on the geometry of the printed product to be printed.

A region may particularly specify at least one track and/or at least one point.

Another aspect of the invention is to select a constant value that yields good predictable results for the printing process parameters, which constant value cannot be changed during the printing process. In particular, a printing process parameter value can be selected for a printing process parameter at which the at least one product property corresponds to the demand profile. In this case, the temperature increase is taken into account during the selection of the printing process parameter values.

In one embodiment, a plurality of energy field data records, in particular ten energy field data records, may be loaded, wherein the superposition is effected using the plurality of energy field data records, and wherein a standstill state is set for the resulting energy field data.

The energy field data can each specify at least substantially one thermal energy, in particular an internal energy. In other embodiments, the energy field data may specify the enthalpy of the assigned region. In another embodiment, the chemical potential in the case of internal energy may be kept out of consideration.

In each case, the thermal behavior of the material can be expressed for a region by means of energy field data. By determining the resulting energy field data, the temperature of the material to be processed can be predicted in the third region, so that the printing process parameter values can be selected according to the thermal behavior or according to the temperature. Thus, a constant and predictable print result can be achieved.

The mentioned regions may be regions of a single layer and/or regions of different layers. This is advantageous because the thermal behavior of course also radiates on other layers, in particular on layers located thereunder and/or thereabove.

In an embodiment, the method may comprise calculating at least one process window map for at least one printing process parameter using the resulting energy field data, wherein the at least one process window map may be used to determine the at least one printing process parameter value.

The at least one process window map may specify a mapping of at least one print process parameter to at least one product characteristic.

The process window map allows for a fast determination of product characteristic values for a given printing process parameter value. Due to the process window map, corresponding printing process parameter values can likewise be determined for the desired product property values. Due to the calculation of the process window map, product characteristics can be guaranteed. In an embodiment, a process window map of at least one printing process parameter value that is constant during the printing process may be associated with at least one product characteristic. Then, at least one printing process parameter value may be determined in such a way that the at least one product property is within the preferred range.

In general, for technical or physical reasons, the printing process parameters cannot be set as desired during the process. For example, changes in beam power are associated with certain reaction times, and changes in beam velocity are affected by beam optics inertia. It is therefore advantageous if a constant printing process parameter value is selected, which results in good product properties throughout the printing process.

The product properties may specifically specify product density, porosity, microstructure, surface roughness, residual stress, deformation, alloy composition, processing time, susceptibility to cracking, and/or production cost.

In an embodiment, the superposition of the first energy field data and the second energy field data may include determining a beam contact point temperature, wherein the beam contact point temperature specifies a temperature on the surface of the product at a particular location at a particular time.

By determining the beam contact point temperature, the temperature may be determined at the location where the energy beam (e.g., laser beam or electron beam) impinges on the material to be melted. Thus, the printing process parameter values may be adapted to the beam contact point temperature, thereby achieving a better melting result or sintering result.

Further, the first and/or second energy field data may be loaded using the beam contact point temperature. Those energy field data corresponding to the energy field measured, created or simulated at a certain beam contact temperature may then be accurately loaded. Subsequently, during the determination of the resulting energy field data, an energy content corresponding to the beam contact point temperature may be removed or absorbed from the energy field data.

Thus, the energy field data to be loaded can be better determined, thereby achieving better melting or sintering results.

In an embodiment, the method may comprise:

-creating simulation data by simulating at least one energy field;

-adjusting the simulation data for experimental data specifying the results of the melting experiment and/or sintering experiment, in particular by performing a random sample consensus (RANSAC) algorithm and/or by cross-correlation;

-creating first energy field data using the adjusted simulation data; and

-storing the first energy field data in a memory device.

In the described embodiments, the energy field data may be determined using experimental data and simulated data. By combining data from experiments and simulations, particularly good results can be achieved. In this case, the simulation data can be adjusted particularly effectively for the experimentally determined data by means of a cross-correlation.

In an embodiment, the base temperature may be assigned to the specifically stored first and/or second energy field data, respectively, wherein the resulting energy field data may be determined while taking into account the respective base temperature.

The base temperature may be determined, for example, by removing or absorbing energy corresponding to the beam contact point temperature. By assigning the base temperature to the energy field data, the effect that the melting process or sintering process has can be determined more accurately. As a result, the resulting energy field data may also be more accurately determined, thereby improving product quality.

In an embodiment, the creation of the simulation data may include:

-determining at least first and second raw simulation data, which may respectively specify energy fields (E1, E2) at different times and/or using at least one different printing process parameter value (25) and/or a different base temperature;

-creating simulation data (21) by numerically superimposing at least first and second raw simulation data of a time and/or at least one printing process parameter value and/or a base temperature different from the time, printing process parameter value and/or base temperature assigned to the raw simulation data.

By superimposing multiple simulated raw simulation data, simulation data for times or configurations that are not explicitly simulated can be determined. The superposition results in an interpolated version of the analog data. As a result, on the one hand, less energy fields need to be simulated, thus saving a lot of computation time, and on the other hand, less memory is consumed for storing simulated data.

In an embodiment, the first and second energy field data may be stored as a matrix, in particular as a vector, preferably as a list or array.

The mentioned memory option provides a particularly efficient storage of energy field data, which allows for a simple loading/saving and/or manipulation of the data.

In an embodiment, the method may include determining resulting temperature field data using the resulting energy field data, wherein a process window map may be determined using the resulting temperature field data.

By determining the resulting temperature field data, which may directly specify the thermal behavior, the printing process parameter values may be determined very quickly.

A range of different printing process parameters is conceivable. In an embodiment, at least one print process parameter may specify

-a beam diameter;

-a beam power;

-a beam velocity;

-the pitch of adjacent tracks or adjacent dots; nominal powder layer thickness;

-the particle size of the powder to be melted or sintered; and/or

-the temperature of the apparatus space.

In an embodiment, the method may comprise controlling an additive manufacturing device for manufacturing a product using at least one printing process parameter value.

Thus, the additive manufacturing device may be directly controlled using the printing process parameter values. To this end, in an embodiment, the method may comprise sending the printing process parameter values to a/the additive manufacturing apparatus, in particular via the internet, an intranet and/or an extranet.

Thus, there is no need for a computer or mobile terminal device, such as a smartphone or laptop, to be directly present near the additive manufacturing apparatus. Rather, a distributed system may be built, which allows a variety of additive manufacturing devices to be controlled from a computer.

In an embodiment, the method may comprise creating a meta-model, in particular by means of interpolating values of a process window map comprising discrete values, wherein the meta-model specifies a relationship between at least one product characteristic and at least one printing process parameter, wherein the determination of the at least one printing process parameter value may be performed using the meta-model.

The process window map may show a discrete image in which product characteristic values are assigned to individual printing process parameter values. Thus, only previously determined values can be queried. By means of interpolation of these values, a meta model can then be created, so that any desired value can be queried. Thus, the meta-model may be seen as a continuous function, in particular an injective or bijective function, which assigns product property values to printing process parameter values.

By creating a meta-model, a rather fine grading can be performed in the parameterization of the additive manufacturing device.

The object is further achieved by means of a computer-readable storage medium containing instructions which, if executed by at least one processor, cause the at least one processor to carry out the method as described before.

The object is also achieved by means of an additive manufacturing device having:

-a memory device, in particular a storage medium, as described before;

-a processor configured to execute instructions stored in a memory device;

-a radiation source,

wherein the processor is configured to configure the radiation source using the printing process parameter values.

Similar or identical advantages result as already described in connection with the method.

The dependent claims lead to further embodiments.

Drawings

Exemplary embodiments of the present invention are described in more detail below based on the drawings. In the attached drawings

FIG. 1: a schematic diagram illustrating an additive manufacturing method;

FIG. 2: a schematic diagram illustrating an additive manufacturing apparatus;

FIG. 3: a schematic diagram is shown showing the superposition of the energy fields of the melting track;

FIG. 4: a flow diagram is shown illustrating the storage of energy field data in a database;

FIG. 5: a flow chart is shown illustrating the determination of printing process parameter values;

FIG. 6: a schematic diagram illustrating a process window diagram;

FIG. 7: a flow chart illustrating a method for controlling a manufacturing apparatus is shown.

Detailed Description

In the following, the same reference numerals are used for the same or similar items.

The following exemplary embodiment describes printing of a plurality of tracks. In the context of the present invention, all described concepts may also be applied to the printing of individual dots.

Fig. 1 schematically shows the printing of an object 1, in which case object data is provided, which describes the object 1 as CAD data various data formats, such as, for example, IGES or ST L, may be used for this purpose, then the object data is "sliced", which means that the software breaks the object data into layers to be printed, in an exemplary embodiment, a machine readable code is subsequently created (e.g. in a so-called build processor) from the "sliced" object data, which code may be read by an additive manufacturing apparatus 10 (see fig. 2), such as a 3D printer.

During printing, printed product 2 is built up from a plurality of printed layers S1, S2, S3 for example, in the S L S method, printed layers S1, S2, S3 are always produced by selective melting of the powder, as described above.

Fig. 2 shows a schematic diagram of an additive manufacturing apparatus 10, which additive manufacturing apparatus 10 may be used to create a printed product 2 as described in relation to fig. 1.

Additive manufacturing apparatus 10 comprises at least one processor 12, a memory device 11, a lifting device 14, and a radiation source 13. In another exemplary embodiment, a network adapter is additionally provided that is configured to connect the additive manufacturing apparatus 10 to the internet, an intranet, or an extranet. In this case, various parameter values, such as printing process parameter values, may be received via the network. The additive manufacturing apparatus 10 may be parameterized or configured by means of the received parameter values. Thus, on the one hand, the parameter values may be received from a server, whereas on the other hand, the parameter values may also be received from different additive manufacturing devices. Thus, it is easy for operators of more than one additive manufacturing device 10 to copy settings to all or a portion of their devices.

The memory device 11 is configured to hold instructions that, when executed by the processor 12, cause the processor 12 to control the radiation source 13. The radiation source 13 may be, for example, a laser source or an electron beam source. Thus, the additive manufacturing device 10 of fig. 2 may be a manufacturing device for a beam melting process or otherwise for a sintering process. The memory device 11 is further configured to store printing process parameter values which parameterize the control of the radiation source 13. For example, the printing process parameter values may specify a beam diameter, a beam power, and/or a spacing of adjacent tracks. Furthermore, the beam speed, i.e. the speed at which the beam moves over the powder to be melted, may be specified by the printing process parameters. In addition to the printing process parameters assigned to the radiation source 13, further printing process parameters assigned to the lifting device 14 are also provided. For example, the printing process parameter value may specify a nominal powder layer thickness of the powder bed.

In the following, the invention for printing different tracks is described in detail. However, all of the exemplary embodiment or embodiments may also be applied to printing of individual dots. Thus, the terms point and track are to be understood as being equivalent in nature with respect to the present invention.

Figure 3 shows a schematic view of three tracks L1, L2, L03, tracks L11, L22, L33 are applied one after the other, where track L41 is applied before track L52 track L63 is in turn applied after track L72 in time during the application of tracks L81, L92, L3 a temperature dependent energy field E, E 'is created for each of tracks L01, L12, L23 for a better overview only the energy fields E, E' of tracks L1, L2 are shown in figure 3 for a better overview the temperature of the material to be melted or sintered or the material in track L1 itself and the environment surrounding track L1 increases when the first track L1 is applied, thus the temperature of the material melted in track L2 increases as the tracks are adjacent or approaching each other before the track L2 is applied.

The same is true in the case of rail L3, where here the influence of the melting or sintering process of rails L1 and L2 is to be taken into account, which has a common influence on the temperature of the material of rail L3 to be melted or sintered the invention is based on the idea of adjusting the printing process parameters according to the melting or sintering process that has taken place in the surroundings of the rails L1, L2 to be applied.

The invention is now explained in more detail on the basis of fig. 4 and 5 fig. 4 shows a flow chart which specifies a method for saving energy field data 20, the application of the individual tracks L1, L2, L3 is simulated in a simulation step 30, in which case the enthalpies are simulated in particular by means of known numerical simulation methods, for example methods based on the lattice boltzmann method.

In an exemplary embodiment, the raw simulation data obtained by means of the simulation comprises a set of used printing process parameter values and a base temperature for each track, wherein the energy field data is calculated at discrete times for the corresponding printing process parameter values and base temperatures. That is, a list of energy field data records is created for individual tracks.

In an exemplary embodiment, an object of an object-oriented programming language is created for raw simulation data of an individual track, where the object may have data and functions as properties. The object is then saved in a corresponding data structure.

The raw simulation data may be queried from the data structure using a query function. In this case, the raw simulation data may be queried as to time and spatial volume using a query function. Querying the raw analog data may include interpolating the saved raw analog data such that a resolution of data returned by the query function may be different from a resolution of the saved raw analog data.

Furthermore, the query function is designed in such a way that: for each query, it returns the original simulation data twice in succession. This is advantageous because the time of the query usually does not correspond exactly to the time of the calculation. Of course, the raw simulation data may also be returned more than twice. For a value X that specifies how many times the original simulation data should be returned, in an exemplary embodiment, for time t, data for time t-X/2 to t + X/2 is returned.

Likewise, the raw simulation data, the different beam contact temperatures and the printing process parameter values may differ from the stored values, so that at least two data records are also returned here.

If the original analog data, the two beam contact temperatures and the two printing process parameter values, such as for example the two power values of the electron beam source, are returned exactly twice, a total of eight data records are therefore returned.

In an exemplary embodiment, the returned raw simulation data is additionally suitable for a common surface. This may be necessary because, for example, the molten bath moves according to the principles of fluid dynamics.

Thus, each of the data records of the raw analog data typically defines a different surface. For eight or more data records, a common surface can be initially determined by means of a weighted average. Subsequently, the eight data records are tilted in such a way that they specify a surface corresponding to the common surface.

These eight data records may then be numerically superimposed by the original analog data and thereby form analog data 21.

The preservation of the raw analog data is very complex. Thus, only a short period of time may be simulated and extrapolation performed more times. As a result, the need for necessary memory can be kept low. In this case, the spatial stretch or spread of the use factor corresponding to the last simulated energy field is extrapolated by a factor that is proportional to the length of thermal diffusion at a given time.

In addition, the illustrated method includes an experimental step 31 in which tracks L1, L2, L03 are applied, respectively, the energy fields of tracks L11, L22, L33 may be determined by measurement in which case the tracks L41, L2, L3 applied in the experiment are applied with the same values of the printing process parameters as used in the simulation step 30, so that the simulation of tracks L1, L2, L3 may be distributed to the tracks L1, L2, L3 of the experimental step 31.

The simulation data 21 are adapted in a control step 32 to experimental data 22, which experimental data 22 specify at least one experimentally determined energy field. In an embodiment, the experimental energy field may be determined, for example, by measuring a cross section of the rail, wherein the melting line is related to the isotherm of the solidus and/or liquidus of the corresponding simulated data.

The adjustment may then be performed by means of cross-correlation. Furthermore, the model search may be by means of the RANSAC algorithm. Thus, in an adjustment step 32, energy field data 20 created taking into account the experimental and

simulation data

21, 22 are created. This ensures a particularly good robustness of the method.

The method of FIG. 4 is performed for a very large number of tracks L1, L2, L3, where printing process parameters, such as materials to be melted or sintered or the printing process parameters described above, are changed, the method of FIG. 4 may be performed at any desired time prior to the actual printing process, furthermore, the database 11 may be provided via a network server, such that data may be queried from any desired location at any time, e.g., via a corresponding API.

The use of the energy field data 20 created by means of fig. 4 will now be described with reference to fig. 5 if a new product 2 should be printed, standard settings for printing process parameters are determined for the first track to be printed, the printing process parameters coming from the base temperature of the material to be melted or sintered in this case, the process window map 40 may be invoked even for the first track L1, as described in connection with fig. 6.

After applying the first track L1, before applying the second track L2, the energy field data 20 are read out from the database 11, which data are created by means of at least substantially the same printing process parameters as the first track L1. as a result, the influence of the first track L1 on the region in which the second track L should be applied can be determined.

Fig. 5 shows in particular the case in which two rails L1, L2 have been applied and a third rail L3 should now be applied.

The first and second energy field data 20, 20' are read out from the database 11 in order to apply a third track L. the first and second energy field data 20, 20' are each assigned to one of the already applied tracks L, L. in a determination step 33, the resulting energy field data 24 are determined by a numerical superposition of the first and second energy field data 20, 20', it is thus determined what the energy field E, E ' assigned to the first and second energy field data 20, 20' has an overall effect on the region of the third track L3 that should be applied.

In step 34, a printing process parameter value 25 is determined based on the temperature T and the resulting energy field data 24. For example, at a temperature increase T compared to the base temperature, a lower beam power and/or an increased beam speed compared to a previously printed track may be set as the printing process parameter value 25.

Thus, process window map 40 may be used to select print process parameter values 25. Fig. 6 shows a schematic diagram of the process window map 40. Fig. 6 shows a coordinate system spanned by two

axes

43, 41. The process window map 40 specifies the relationship of the individual values of the print process parameters 41 to the product characteristic values 44, 44'. Only one product characteristic 43 is shown in the exemplary embodiment shown.

In other exemplary embodiments, the process window map 40 may specify a multi-dimensional parameter range specifying a plurality of print process parameters in relation to a plurality of product characteristics.

The process window map 40 may be created in different ways. For example, the process window map 40 may be created experimentally. To experimentally determine the process window map 40, a plurality of printed products 2 are printed using different printing process parameter values 25. The printed product 2 can then be investigated in a laboratory so that the product characteristic values are accurately determined.

In an exemplary embodiment, the process window map 40 may be determined by means of a simulation method. Such simulations may be performed with known relationships of printing process parameters 41 to product characteristics 43. Therefore, expensive experiments can be prevented.

In another exemplary embodiment, the process window map 40 may be created using the resulting temperature field data 24. in this case, during the creation of the process window map 40, the effect of, for example, temperature of the adjacent tracks L1, L2 on the track L3 to be applied is considered.

The process window map 40 constitutes discrete quantities of the print process parameter values 25 and associated product characteristic values. Additionally, the process window map 40 may contain information regarding which print process parameter values 42, 42' specify an acceptable quality range 44. Printing process parameter values outside the quality range 44 result in unsatisfactory product. The mass range 44 is specified, for example, by means of two or more limit values 44, 44'. The limit values 44, 44' then specify the outer limits of the mass range 44.

The meta-model 40 may be further created from the process window map 40. The discrete points of the process window map 40 may be converted to a continuous meta-model by known methods (e.g., stitching interpolation or neural network training).

Thus, the meta-model may also be used to select the printing process parameter values 25.

Fig. 7 shows another exemplary embodiment, in which the additive manufacturing device 10 is controlled by means of the printing process parameter values 25, first, two sets of energy field data 20, 20' are read out anew from the database 11, which data can be assigned to respectively adjacent tracks L1, L2 of the track L3 to be applied.

In step 50, a process window map 40 is created using the energy field data 20, 20'. In this case, in step 50, the resulting energy field data 24 used as described with respect to fig. 6 to create the process window map 40 is determined. In step 51, the meta-model 45 may be calculated by interpolation by means of values from the process window map 40.

In step 52, the printing process parameter values 25 for applying the single track L3 are determined by means of the meta-model 45, in which case the desired product characteristics are determined by the user, and the corresponding printing process parameter values 25 are determined.

In step 52, the additive manufacturing device 10 is set up and controlled using the determined printing process parameter values 25.

List of reference marks

1 object/cup

2 print product

103D printer/additive manufacturing device

11 memory device/database

12 processor/computing device

13 radiation source

14 lifting device

20. 20' energy field data

21 analog data

22 data of experiments

23 energy field data

24 resultant energy field data

25 printing process parameter values

30 simulation step

31 Experimental procedure

32 adjustment step

33 determination of the resulting field data

34. 53 determination of printing process parameters

40 process window map

41 print Process parameters

42, 42' printing process parameter limit values

43 product Properties

44, 44' limit value of product property

45-element model

50 steps for creating a Process Window map

51 interpolation step

52 step for determining

54 control step

S1, S2, S3 print layer

E. E' energy field

T beam contact temperature

L1, L2, L3 orbit

Claims

1. A method for determining at least one printing process parameter value (25) for a beam melting process and/or a beam sintering process, the method having the following steps:

-loading first and second energy field data (20, 20') of a melting or sintering process from a memory device (11), which first and second energy field data (20, 20') are respectively assigned to, in particular, adjacent energy fields (E1, E2) of at least one region (L1, L2, L3), in particular at least one track and/or at least one point, preferably 10 tracks;

-determining (33) result energy field data (24) by digitally superimposing the first energy field data (20) and the second energy field data (20');

-determining (34) at least one printing process parameter value (25) for at least one printing process parameter of an additive manufacturing device (10) using the resulting energy field data (24).

2. The method of claim 1, wherein:

calculating at least one process window map (40) for at least one printing process parameter (41) using the resulting energy field data (24), wherein the at least one printing process parameter value (25) is determined using the at least one process window map (40).

3. Method according to one of the preceding claims, in particular according to claim 2, characterized in that

A/the at least one process window map (40) specifies a mapping of the at least one printing process parameter (41) to at least one product characteristic (43).

4. Method according to one of the preceding claims, characterized in that

Superimposing the first energy field data (20) with the second energy field data (20') comprises determining a beam contact point temperature (T), wherein the beam contact point temperature (T) specifies a temperature on a surface of the product (2) at a specific location at a specific time.

5. Method according to one of the preceding claims, characterized in that

The energy field data (20, 20') each specify essentially at least one thermal energy, in particular an internal energy.

6. Method according to one of the preceding claims, characterized in that

-creating simulation data (21) by simulating at least one energy field (E, E');

-adjusting the simulation data (21) for experimental data (22) specifying the results of melting experiments and/or sintering experiments, in particular by performing a random sample consensus (RANSAC) algorithm and/or by cross-correlation;

-creating the first energy field data (20, 20') using the adjusted simulation data; and

-storing the first energy field data (20, 20') in the memory device (11).

7. Method according to one of the preceding claims, characterized in that

Assigning a base temperature to the specifically stored first energy field data and/or second energy field data (20, 20'), respectively, and wherein the resulting energy field data (20, 20') can be determined while taking into account the respective base temperature.

8. Method according to one of the preceding claims, in particular according to claim 7, characterized in that

Creating the simulation data (21) comprises:

-determining at least first and second raw simulation data specifying energy fields (E1, E2) of a simulated melting process at different times and/or using at least one different printing process parameter value (25) and/or at different base temperatures, respectively;

-creating the simulation data (21) by numerically superimposing at least the first and second raw simulation data at a time and/or at least one printing process parameter value and/or base temperature different from the time, printing process parameter value and/or base temperature assigned to the raw simulation data.

9. Method according to one of the preceding claims, characterized in that

The first energy field data and the second energy field data (20, 20') are stored as a matrix, in particular a vector, preferably a list or an array.

10. Method according to one of the preceding claims, characterized in that

Determining resulting temperature field data (24) using the resulting energy field data (20, 20'), wherein the process window map (40) is determined using the resulting temperature field data (24).

11. Method according to one of the preceding claims, in particular according to claim 3, characterized in that

A/the product property (43) specifies a product density, porosity, microstructure, surface roughness, residual stress, deformation, alloy composition, processing time, easy cracking, particle size of the powder to be melted and/or production cost.

12. Method according to one of the preceding claims, in particular according to claim 3, characterized in that

The at least one printing process parameter (41) specifies

-a beam diameter;

-a beam power;

-a beam velocity;

-the pitch of adjacent tracks or adjacent dots;

-nominal powder layer thickness; and/or

-the temperature of the apparatus space.

13. Method according to one of the preceding claims, characterized in that

For controlling (52) an additive manufacturing device (1) for manufacturing a product (2) using the at least one printing process parameter value (25).

14. Method according to one of the preceding claims, characterized in that

-sending the at least one printing process parameter value (25) to the additive manufacturing device (1), in particular via the internet, an intranet and/or an extranet.

15. Method according to one of the preceding claims, characterized in that

-creating a meta-model (45), in particular by means of interpolation (51) of values of a process window map (40) comprising discrete values, wherein the meta-model (45) specifies a relation between at least one product property (43) and at least one printing process parameter (41), wherein the determination of the at least one printing process parameter value (25) is performed using the meta-model (45).

16. A computer-readable storage medium (11) containing instructions which, if executed by at least one processor (12), cause the at least one processor (12) to implement the method according to one of the preceding claims.

17. An additive manufacturing apparatus (10) having:

-a memory device (11), in particular according to claim 16;

-a processor (12) configured to execute instructions stored in the memory device (11);

-a radiation source (13),

wherein the processor (12) is configured to configure the radiation source (13) using at least one printing process parameter value.